Solar Collector

ABSTRACT

This invention presents a trough-shaped solar collector. The solar collector includes a trough-shaped reflector for concentrating incoming solar rays upon a focal axis. The reflector includes a flexible reflective film having a concave reflective surface. The reflective film is braced by a bulkhead-and-rod frame that is disposed inside the concave space created by the reflective surface of the reflective film. The reflective film is placed in longitudinal tension using spring clamps, and is intermediately held against bulkhead members using straps. The solar collector has a variety of support rod patterns to maintain the integrity of the bulkhead-and-rod frame. The solar collector may be collapsed into a smaller space for shipping or storage.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent application Ser. No. 12/707,063 filed on Feb. 17, 2010.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

This invention was made with government support under grant 2011-33610-30472 awarded by the US Department of Agriculture (USDA). The government has certain rights in the invention.

APPENDIX

Not Applicable.

FIELD OF THE INVENTION

This invention generally relates to collectors and, more specifically, to an improved trough-shaped solar collector structure and an improved method for assembly and maintenance.

BACKGROUND OF THE INVENTION

Various solar collectors have been used to capture solar energy for use. Such solar collectors employ reflectors or refractors to concentrate incoming solar rays upon a focal point or focal axis. Solar collectors employing reflectors with parabolic reflective surfaces are usually less expensive and thus economically more attractive than ones with refractors, such as lenses.

Reflectors for solar collectors usually include a reflective material and support structures therefor. Various materials are employed for the reflective material, such as glass, segmented sheets, or molded composite plastic materials. As the size of reflectors has increased to produce significant quantities of energy from solar energy, the weight and size of the reflector structure have also increased. As a consequence, the cost associated with the manufacture of reflectors economically prohibits a large scale adoption of solar collectors.

Many known solar collectors employ longitudinally extending trough-shaped reflectors. The trough-shaped reflectors are of parabolic cross section or configuration. The known trough-shaped reflectors are not only difficult to fabricate, but also require the use of relatively expensive reflective materials and/or heavy support structures. Accordingly, none is economically attractive.

SUMMARY OF THE INVENTION

The present invention has been made to solve the above-mentioned problems occurring in the prior art, and it is an object of the present invention to provide a solar collector that can be manufactured with light weight and at low cost. It is another object of the present invention to provide a trough-shaped or parabolic-shaped solar collector that can be easily fixed or replaced.

To achieve the above object, in one aspect of the present invention, there is provided a reflector for a solar collector. The reflector includes a reflective member and a support member. The reflective member has a concave reflective surface for reflecting solar rays. The support member braces the reflective member such that the reflective surface is kept concave to form a generally trough or parabolic shape. The support member contacts the concave reflective surface.

In a preferred embodiment of the present invention, the support member includes two end bulkheads. Each of the end bulkheads has a generally parabolic outer contour. The generally parabolic outer contour contacts the concave reflective surface. Additionally, the support member can also include one or more middle bulkheads between the end bulkheads. The middle bulkhead also has a generally parabolic outer contour that contacts the concave reflective surface. Additionally, the support member includes a longitudinally extending spine that connects between the end bulkheads. Preferably, the spine supports the end bulkheads such that the distance between the end bulkheads is kept. Additionally or alternatively, the support member can also include a bracing or support wire attached between the end bulkheads under tension. Preferably, the bracing wire has a collar or other means to avoid slippage.

In a preferred embodiment, the reflector includes a clamp mechanism which is self-tightening. The self-tightening clamp mechanism can utilize springs for attaching the reflective member to the support member under tension. Preferably, the spring is held in compressed position. The reflector can include a yoke attached to the reflective member. The spring has a yoke receiving portion that can engage with the yoke. Alternatively, the reflector can include a binder clip attached to the reflective member. In this alternative embodiment, the spring has a clip receiving portion for engaging with the binder clip. As an alternative to the spring, flexible cordage such as a bungee cord also can be used.

In a preferred embodiment, the reflective member is a reflective membrane such as flexible film. The reflective member can be made of plastic, aluminum, stainless steel, or steel. The reflective membrane can be made of thin material, the shape of which is kept by tension. Alternatively, the reflective membrane can be made of thicker material which does not wrinkle.

In a preferred embodiment, the support member is made of webs with most material removed.

In a preferred embodiment, the reflector includes a mount on which the support member can be installed. Preferably, the mount includes a first tracking motor and a second tracking motor for driving the support member to rotate toward the sun. Each of the first tracking motor and the second tracking motor has an angle sensor. The first tracking motor and the second tracking motor communicate with each other. Additionally or alternatively, the mount includes a first extension arm and a second extension arm. The support member is fixedly attached to the first and second extension arms. As an alternative to the use of two tracking motors, the reflector can include a single motor for driving the first and second extension arms to rotate such that the first and second extension arms are simultaneously rotated so as not to twist the reflector. Preferably, the mount provides the support member a stored position such that the reflector can be moved between an operating position and a stored position.

In another aspect of the present invention, there is provided a collector including a novel reflector according to the present invention and a receiver. The receiver can be one of various receivers. In a preferred embodiment, the receiver can produce both electric power and heat. In this preferred embodiment, the receiver includes a plurality of photovoltaic cells for absorbing the light and converting the light into electric power. The receiver further has a fluid conduit for collecting heat from the photovoltaic cells.

In an alternative embodiment, the collector according to the present invention can utilize a receiver that simply produces heat only. In this alternative embodiment, the receiver has a light absorbing member for absorbing the light and converting the light into heat. The receiver further has a fluid conduit for collecting heat from the light absorbing member.

In a preferred embodiment, the receiver is a V-shaped receiver. Alternatively, the reflector according to the present invention can be used with a box-shaped receiver. Yet alternatively, the receiver can be an evacuated receiver.

In yet another aspect of the present invention, there is provided a receiver for producing both electric power and heat. The receiver includes a plurality of photovoltaic cells for absorbing light and converting the light into electric power. The receiver also includes a fluid conduit for collecting heat from the plurality of photovoltaic cells.

In a preferred embodiment of the present invention, the receiver further includes a connector strip. The photovoltaic cells are installed on the connector strip in a row. Preferably, the connector strip is punched and wrinkled-raised, and the photovoltaic cells are placed between neighboring wrinkles. Each wrinkle is connected to its respective next photovoltaic cell such that all of the photovoltaic cells are in series.

In a preferred embodiment, the receiver includes two connector strips: a first connector strip and a second connector strip. The photovoltaic cells comprise two rows of photovoltaic cells, each row installed on its respective one of the first and second connector strips. Preferably, the receiver includes a V-shaped base strip having two inner surfaces angled with each other. Each of the first and second connector strips is mounted on one of the two inner surfaces of the V-shaped base strip. Preferably, the receiver further has a cover. The fluid conduit is defined between the cover and the V-shaped base strip such that the fluid conduit extends longitudinally.

The receiver can further have a light-permeable front face member. The front face member is mounted on the base strip such that the front face member protects the plurality of photovoltaic cells. In the embodiment employing a V-shaped base strip, the light-permeable front face member is mounted on the V-shaped base strip such that the front face member covers the inner surfaces. The light-permeable front face member can be made of glass.

Alternatively, the receiver can have a light-permeable tube. The photovoltaic cells and at least part of the fluid conduit are located within the tube. The light-permeable tube can be made of glass. Preferably, the tube is air-evacuated.

In yet another aspect of the present invention there is provided a receiver that can produce heat. The receiver includes a light absorbing member for absorbing light and converting the light into heat. The receiver also has a fluid conduit for collecting heat from the light absorbing member. The light absorbing member can be made of black metal.

In yet another aspect of the present invention there is provided a method of manufacturing a receiver. A plurality of photovoltaic cells is installed on a connector strip. The installation is performed by punching and wrinkling the connector strip, and placing the photovoltaic cells on the connector strip such that each of the photovoltaic cells is placed between neighboring wrinkles. The wrinkles of the connector strip can be electrically connected (solder, epoxy) to their respective next photovoltaic cells such that the photovoltaic cells are in series. The connector strip is installed on a base strip such that the connector strip and the base strip is electrically insulated and thermally conducted.

Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an elevated side view of an embodiment of a solar collector according to the present invention.

FIG. 2A is a perspective view of the support frame of the reflector of the solar collector of FIG. 1.

FIG. 2B is a perspective view of a portion of a bulkhead of the present invention.

FIG. 2C is a larger perspective view of the support frame of FIG. 2A.

FIG. 3 is an enlarged, partial, perspective view of the reflector of the solar collector of FIG. 1 with the spine omitted.

FIG. 4 is an enlarged top view of the spring illustrated in FIG. 3.

FIG. 5 is a perspective view of an embodiment of a solar collector according to the present invention, which is installed on a reflector mount.

FIG. 6 is a perspective view of the solar collector of FIG. 5 in a stored position.

FIG. 7A is a side view of an alternative clamping system that may be used to allow for a rapid change of reflective media.

FIG. 7B is a side view of a second, alternative clamping system that may be used to allow for a rapid change of reflective media.

FIG. 7C is a perspective view of an alternate clamp 80.

FIG. 8A is a perspective view of an embodiment of a receiver with two rows of photovoltaic cells.

FIG. 8B schematically shows how to assemble the receiver of FIG. 8A.

FIG. 8C shows the receiver of FIG. 8A bent into a “V” shape.

FIG. 9A is a front view of an alternate receiver embodiment of the present invention.

FIG. 9 B is a side view of the alternate receiver embodiment of FIG. 9A.

FIG. 10 is an elevated view of another embodiment of a solar collector.

FIG. 11A is an elevated view of the bulkhead assembly of the solar collector embodiment shown in FIG. 10.

FIG. 11B is a plan view of a bulkhead rib of the bulkhead assembly of FIG. 11A.

FIG. 11C is a plan view of a base of the bulkhead assembly of FIG. 11A.

FIG. 11D is a section of the bulkhead assembly taken along line 11D of FIG. 11A.

FIG. 12A is a section view of a bulkhead assembly of an alternate embodiment.

FIG. 12B is a section view of a spacer element of an alternate embodiment.

FIG. 13A is a top plan view of a bulkhead rib element of an alternate embodiment prior to bending.

FIG. 13B is a side plan view of the bulkhead rib element of the embodiment of FIG. 13A after bending.

FIG. 13C is a section view taken along line 13C of the alternate embodiment of FIG. 13A, wherein the bulkhead rib element is further assembled into a bulkhead assembly.

FIG. 14A is an enlarged side plan view of portion 14A-B-C of FIG. 10.

FIG. 14B is an enlarged front plan view of portion 14A-B-C of FIG. 10.

FIG. 14C is an enlarged top plan view of portion 14A-B-C of FIG. 10.

FIG. 15A is an enlarged side plan view of portion 15A-B of FIG. 10.

FIG. 15B is an enlarged top plan view of portion 15A-B of FIG. 10.

FIG. 16A is a view of the first set of rods which were omitted for clarity from the embodiment of FIG. 10.

FIG. 16B is a view of a second set of rods which were omitted for clarity from the embodiment of FIG. 10.

FIG. 16C is a view of a third set of rods which were omitted for clarity from the embodiment of FIG. 10.

FIG. 17A is a right plan view of the embodiment of FIG. 10 in a partially-folded position, providing certain details which were omitted from FIG. 10 for clarity.

FIG. 17B is a right plan view of the embodiment of FIG. 10, providing certain details which were omitted from FIG. 10 for clarity.

FIG. 18A is a front plan view of the embodiment of FIG. 10 in a partially-folded position, providing certain details which were omitted from FIG. 10 for clarity.

FIG. 18B is a front plan view of the embodiment of FIG. 10, providing certain details which were omitted from FIG. 10 for clarity.

FIG. 19A is a rear plan view of the embodiment of FIG. 10, showing a foam pattern applied to the back of reflective film 104.

FIG. 19B is a section view of applied foam taken along line 19B of FIG. 19A.

FIG. 19C is an elevated view of a foam shaping tool.

FIG. 19D is a rear plan view of the embodiment of FIG. 10, showing a flange fixed to the back of reflective film.

FIG. 19E is a section view taken along line 19E of FIG. 19D, showing the flange, spacer, and reflective film.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 there is shown a solar collector 10. The solar collector 10 includes a reflector 20 for concentrating incoming rays 2 upon a focal axis. The reflector 20 extends longitudinally to form a generally trough shape as seen in FIGS. 2A, 2C, 3, 5, and 6. The solar collector 10 also includes a receiver 60 longitudinally extending along the focal axis. The receiver 60 functions to convert the solar energy into electricity and/or heat. The receiver 60 can include solar cells, thermal collector, or both. The reflector 20 includes a reflective membrane 30 braced with a support frame 40. The support frame 40 includes a spine 42 and bulkheads 44, 46, 48.

FIG. 2A shows the support frame 40. The spine 42 extends longitudinally, connecting and supporting the bulkheads 44, 46, 48 such that the distance between neighboring bulkheads can be kept. Each of the end bulkheads 44, 46 and the middle bulkhead 48 has an outer (bottom) contour in a trough or parabolic shape (See FIG. 2B) so that the support frame 40 can have a longitudinally extending trough or parabola-like outer (bottom) contour. The reflective membrane 30 is kept in constant tension and in contact with the outer (bottom) contour of the support frame 40 so that the reflecting membrane 30 can be kept in a longitudinally-extending trough or parabola-like shape.

The reflective membrane 30 can be made of flexible material, such as plastic film that is as reflective as a mirror. Preferably, the flexible material is hail-resistant and stiff enough to prevent or reduce wrinkling problems which may deteriorate the solar ray concentrating performance of the reflector 20. The flexible material is also preferably light in weight. One example of membrane material that can make the present invention practical includes polyethylene up to about 0.050″ thick. Another example of a reflective membrane 30 is the use of a reflective film sold under the trade name REFLECTECH® Mirror Film, which reflective film can then be laminated to stiff media such as thin sheets of metal or thin sheets of stiff plastic.

The support frame 40 is made from tubular or flat stock metal and internal wire bracing. The spine 42 and the bulkheads 44, 46, 48 have place for bracing wires 50, 51B or tubes 50A (FIGS. 2A, 2C) to fit and the stock is cut to flex at the point of connection. The bracing wires 50, 51B or tubes 50A longitudinally extend, connecting the bulkheads 44, 46, 48. The bracing wires 50, 51B are installed and stay under tension, while tubes 50A remain rigid. The outer (bottom) contour of the bulkhead 44, 46, 48 together with the bracing tubes 51A keep the reflective membrane 30 in the trough or paraboloidal shape. Spacing between the bulkhead 44, 46, 48 is maintained by both spine 42 and by bracing wires 50, 51B (See FIGS. 2A, 2C). The bracing wires 50, 51B can have collars (not shown) crimped on to avoid slippage relative to the bulkheads 44, 46, 48. The spine 42 and the bulkheads 44, 46, 48 are essentially webs with intervening material removed.

The reflective membrane 30 is attached to the outside of bulkheads 44, 46, 48 by means of a clamp mechanism. In other words, it is critical to the invention that the bulkheads 44, 46 are disposed against the interior surface of reflective membrane 30. It is appreciated that this geometry has a disadvantage of blocking some light. However, it is believed that the device may be made of a longer dimension to compensate for the loss of energy. Moreover, as will be seen below, there are significant advantages in construction, maintenance, and material utilization that have not been appreciated by the prior art. Preferably, the clamp mechanism is self-tightening such that the harder it is pulled, the tighter it grips the membrane 30. Preferably, the self-tightening clamp mechanism can be embodied by utilizing elastic elements such as springs, or flexible cordages like a bungee cord.

As shown in FIG. 2B, the bulkhead 44 portion shown has a radially-extending portion shown generally by E, intersecting an arcuate surface shown generally at A. It is key to the invention that arcuate surface A be disposed on the concave interior side of reflective membrane 30. In this arrangement, it is acknowledged that the radially-extending portion E may block some light. In other words, all of the arcuate surface A of bulkheads 44, 46, 48 contact the concave side of reflective membrane, as opposed to contact with the convex side of reflective membrane 30.

In the exemplary embodiment illustrated in FIGS. 3 and 4, the self-tightening clamp mechanism is embodied by using springs 54. The spring 54 has a stabbing portion 54 a that stabs into the bulkheads 44, 46, 48. The spring 54 also has a feature 54 b that holds the spring 54 in compressed position. The spring 54 also has a yoke receiving portion 54 c that can engage with a small yoke 52. The yokes 52 are attached to the reflective membrane 30 with adhesive or may be welded. Attachment of the reflecting membrane 30 can be done by turning the support frame 40 upside down, rolling the reflective membrane 30 across and attaching the yokes 52 to the springs 54 as reflective membrane 30 is rolled. Once in place, springs 54 are released starting in the center. A kink 54C in the spring 54 holds yoke 52 in place. If the reflective membrane 30 gets damaged for example in a wind storm, it can be easily fix or replaced. Alternatively, binder clips can be used instead of the yokes 52 glued onto the reflecting membrane 30.

FIGS. 5 and 6 show the reflector 20 installed on a reflector mount 70. The reflector mount 70 has a pair of tracking motors 74, a controller 75 for controlling the tracking motors 74 in order to move them synchronously, and a pair of mount bases 76. The tracking motors 74 are installed in their respective mounting bases 76. The tracking motors 74 drive their respective bulkheads 44, 46 to rotate. The tracking motors 74 on each end function to turn the reflector 20 toward the sun. Each tracking motor 74 has an angle sensor (not shown) and the two tracking motors 74 communicate with each other or with a central controller 75 so as not to twist the reflector 20. Because of this, the reflector 20 does not have to be very stiff torsionally. Because multiple solar collectors 10 may be arranged linearly (in series), it is preferred that the second tracking motor 74 on one unit serve simultaneously as the first tracking motor 74 on the next unit. Therefore, as seen in FIG. 6, the total number of motors required for a linear arrangement of solar collectors is equal to the total number of collector units 10 that are in a particular line plus 1 (one additional motor at the end of each linear series). The profile of bulkhead 44 shown in FIG. 2B has been simplified for clarity in FIGS. 3 and 5. However, it is fully intended that the bulkhead 44 shown in FIGS. 3 and 5 have the same profile as that shown in FIG. 2B.

In addition, extension arms (not shown) would allow additional height so that space underneath can be used. In rain or other inclement weather, the reflector 20 is simply rotated to face the ground to assume a stored position as shown in FIG. 6.

As seen in FIG. 7A, an alternate clamping system is shown. Reflective membrane is shown generally at 30. Reflective membrane 30 is wrapped at one end around slat 84. Slat 84 provides a surface for gripping reflective membrane 30 and allows for a consistent tension along the width of reflective membrane 30. Slat 84 and an end portion of reflective membrane 30 are gripped by clamp 80. Clamp 80 preferably has an open position for receiving slat 84 and reflective membrane 30, and a closed position for securely gripping slat 84 and reflective membrane 30. Tensioner 82 is any device disposed between a bulkhead 44, 46, 48 and clamp 80 to position clamp 80 relative to a bulkhead 44, 46, 48. Tensioner 82, preferably a spring, is attached between clamp 80 and bulkhead 44. Tensioner 82 may also be an adjustable locking pivot arm, as shown in FIG. 7B. Preferably, tensioner 82 is positioned to apply tension either parallel to or in line with the surface of reflective membrane 30. Tensioner 82 provides consistent tension to reflective membrane 30 to maintain reflective membrane 30 under tension. This clamping system allows for extremely fast replacement of reflective membrane 30. It further permits reflective membrane 30 to experience relatively constant tension despite variations in temperature that may cause expansion and contraction of reflective membrane 30 and or support 40.

In FIG. 7B, reflective member 30 is wrapped around slat 84, which is then surrounded by clamp 80. Clamp 80 is attached to tensioning arm 87A of tensioner, shown generally at 82. Tensioner 82 may comprise a first tensioning arm 87A, having finger grips G, a tensioner bracket 87B, ratchet guide R and pivot pin P. Tensioner bracket 87B is disposed in tension against bulkhead 44, via tensioning arm 87A which pivots about pivot pin P in an arc defined by ratchet guide R. To tension reflective member 30, a user may grip tensioning arm 87 using finger grips G, and pull in a direction away from bulkhead 44. As tensioning arm 87A rotates about pivot pin P along an arc defined by ratchet guide R, tension is placed on reflective member 30, and held at a position by ratchet guide R. It should be appreciated that as tensioning arm 87A rotates, an angled side of clamp 80 contacts reflective member 30 to secure it between slat 84 and claim 84. With this arrangement, it is possible to stretch reflective member 30. To release tension on reflective member 30, a user may grip tensioning arm 87 using finger grips G, and move tensioning arm 87A towards bulkhead 44. As tensioning arm 87A rotates about pivot pin P along an arc defined by ratchet guide R, tension is released on reflective member 30.

In FIG. 7C, clamp 80 is provided with an open angled jaw on one end, and a groove 81 on the other end. A rod 84A is disposed within open angled jaw shown generally at J to provide a friction grip for retaining reflective member 30. When rod 84A is moved to the wider space within open angled jaw J, the friction grip on reflective member 30 is released, to permit maintenance. Groove 81 may receives a male member such as a spring with a kink, such as that shown at 54C in FIG. 4, attached to a bulkhead 44, 46, 48. It can be appreciated that as the tension on clamp 80 is increased via a spring, rod 84A will rotate against angled surface of J causing increased clamping force on reflective member 30. In other words, tensioner 80 is self-tightening.

Once reflective member 30 is clamped and tightened, the concave reflective surface of reflective member 30 assumes a parabolic shape due to forced contact against the outer parabolic contour of bulkheads 44, 46, 48. It is important to the invention that the reflective member 30 is held in tension by some kind of tensioning device against bulkheads 44, 46, 48, rather like a tent is held in tension, and is not fixed against bulkheads 44, 46, and 48 by screws or other permanent fastener. Therefore, it is theoretically possible for reflective member 30 to slide relative to bulkheads 44, 46, and 48 to accommodate, for example, thermal-related movement.

The reflector 20 according to the present invention can be used with various types of solar receivers. Although the reflector 20 of the present invention can be best used with a novel receiver 60 according to the present invention as described below in details, it can also be advantageously used with various known types of solar receivers. Examples of such known types of solar receivers can include a box-shaped receiver having a box with reflecting internal walls to re-reflect light to one strip of solar cells. Commercially available examples of known types of solar receivers can also include evacuated type of solar receivers. Such known receivers are not explained in details in this application.

A receiver 60 according to the present invention can use solar cells, thermal collector, or both.

In the embodiment illustrated in FIGS. 8A, 8B, and 8C, the receiver 60 includes two rows of photovoltaic cells 62. Alternatively, a single row of photovoltaic cells 62 can also be employed. Yet alternatively, three or more rows of photovoltaic cells 62 can also be employed. Each of the rows of photovoltaic cells 62 are installed on a connector strip 64. Although the connector strip 64 can be made of copper, tin plated steel or some type of foil can be preferred because of cost consideration.

First, the connector strip 64 is punched and wrinkled-raised as best seen in FIG. 8B. According to Step A, a first photovoltaic cell 62A is placed on adhesive 68 which is layered above base strip 66. Then, according to Step B, connector strip 64 is placed on adhesive 68. At the same time, electrically-conductive epoxy (not shown) is applied to the underside of 64A so that as connector strip 64 is placed on adhesive 68 in Step B, the underside of wrinkle 64A is placed in electrical contact or electrical communication with the top of first photovoltaic cell 62A. Next, according to Step C, an electrically-conductive epoxy (not shown) is applied to the underside of second photovoltaic cell 64C, and then second photovoltaic cell is placed on the connector strip 64 that was applied in Step B. Next, according to Step D, electrically-conductive epoxy (not shown) is applied to the underside of 64A so that as connector strip 64 is placed on adhesive 68 in Step D, the underside of wrinkle 64A is placed in electrical contact or electrical communication with the top of second photovoltaic cell 62C. Then, according to Step E, an electrically-conductive epoxy (not shown) is applied to the underside of third photovoltaic cell 64E, and then third photovoltaic cell 64E is placed on the connector strip 64 that was applied in Step D. Next, according to Step F, electrically-conductive epoxy (not shown) is applied to the underside of 64A so that as connector strip 64 is placed on adhesive 68, the underside of wrinkle 64A is placed in electrical contact or electrical communication with the top of third photovoltaic cell 62E. Then, according to Step G, an electrically-conductive epoxy is applied to the underside of fourth photovoltaic cell 64G, and then fourth photovoltaic cell 64G is placed on the connector strip 64 that was applied in Step F. The photovoltaic cells 62 are adhered for high thermal and electrical conductivity.

As best seen in FIG. 8B, the wrinkles 64 a of the connector strip 64 are cut, bent, and soldered or epoxied to their respective next cells 62 so that all photovoltaic cells can be in series.

In the illustrated embodiment, two connector strips 64, each having a row of photovoltaic cells 62 installed thereon, are placed on a base strip 66. The base strip 66 is preferably thermally conductive. The two connector strips 64 are attached to the base strip 66 with adhesive 68. The adhesive 68 is preferably electrically insulating but thermally conducting. It may be possible to perform the installation of the two connector strips 64 on the base strip 66 at the same time with the installation of the two rows of photovoltaic cells 62 on the two connector strips 64.

In the embodiment as illustrated in FIG. 8C, the base strip 66 is bent into “V” shape with a longitudinally extending flange 66A at each lateral end. The advantages of this “V” shape configuration includes that light not absorbed in one side can be reflected toward the other side and there get absorbed, whereby increasing the overall absorption efficiency.

A V-shaped cover 70 is soldered on to the flanges 66A to form a water jacket 71 between the cover 70 and the base strip 66. Fluid, typically water, can flow through the water jacket to cool the photovoltaic cells 62. Accordingly, the receiver 60 can produce electricity as well as hot water.

The receiver 60 can have a semicircular front (not shown) made of glass to exclude dirt. Alternatively, the receiver 60 can be installed into a glass tube (not shown). The glass tube can also be evacuated so as to cut down on heat losses.

As an alternative to photovoltaic cells 62, other types of energy converting members can be used, such as black metal for simply absorbing heat.

In FIGS. 9A and 9B, an alternate embodiment of a receiver 60 is provided. In particular, front plate 90 is provided with vacuum port 92 for evacuating the receiver. O-ring 98 provides a seal between front plate 90 and glass tube 94. Similarly, o-ring 98 provides a seal between back plate 100 and glass tube 94. Disposed within glass tube 94, light receiver plates 62 are in thermal communication with copper tube 96. Copper tube 96 is adapted for the flow of liquid, preferably water. The receiver shown in FIGS. 9A and 9B may be used in lieu of the receiver shown in FIGS. 8A-8C.

As seen in FIG. 10, a solar collector is shown generally at 100. Solar collector 100 has upper reflector sheet 102 and lower reflector sheet 104 that collect and concentrate light at a focus F, a photovoltaic collector, which is mounted on upper rod 106. Upper rod 106 may be a continuous rod that extends through posts 130, 132, 134, 136, and 138 respectively, or may be a series of rod segments that are connected to the posts 130, 132, 134, 136, and 138. As also shown in FIG. 10, post 130 is connected to diagonal rods 152 and 154; post 132 is connected to diagonal rods 156 and 158; post 134 is connected to diagonal rods 160 and 162; post 136 is connected to diagonal rods 164 and 168; post 138 is connected to diagonal rods 168 and 170.

Longitudinal spine 108 is connected to posts 130, 132, 134, 136, and 138, and is further connected to end bulkhead assembly 180, middle bulkhead assembly 182, middle bulkhead assembly 184, middle bulkhead assembly 186, and end bulkhead assembly 188. End bulkhead assembly is connected to diagonal rods 152 and 154. Middle bulkhead assembly 182 is connected to diagonal rods 156 and 158. Middle bulkhead assembly 184 is connected to diagonal rods 160 and 162. Middle bulkhead assembly 186 is connected to diagonal rods 164 and 166. End bulkhead assembly 188 is connected to diagonal rods 168 and 170.

Further connecting to the bulkhead assemblies 180, 182, 184, 186, and 188, respectively are intermediate rods 140 and 142, and end rods 194 and 196. As evident from FIG. 10, the bulkhead assemblies 180, 182, 184, 186, and 188 each have an outer convex contour. Reflector sheet 102 and reflector sheet 104 each has a concave shape defined by contact with the outer convex contour of the bulkhead assemblies 180, 182, 184, 186, and 188.

With respect to the bulkhead assemblies, 180, 182, 184, 186, and 188, respectively, FIGS. 11A, 11B, 11C, and 11D provide additional information. Each bulkhead assembly, generally referred to at 110 has a first bulkhead rib 112, and a second bulkhead rib 114. Each rib is provided with plurality of tab cutouts 118, and tab slits 116. It is preferred that the order of tab cutouts 118 and tab slits 116 are staggered with respect to first bulkhead rib 112 and second bulkhead rib 114 such that the tab cutout 118 of first bulkhead rib 112 may be bent and extended through a complimentary tab slit 116 on second bulkhead rib 114, and then bent down again (as seen in FIG. 11A). Similarly, a tab cutout 118 on second bulkhead rib 114 may be bent and extended through a complimentary tab slit 116 on first bulkhead rib 112. The end of each tab is fixed by a fastener R, as best seen in FIG. 11D. It is preferred that fastener R be a rivet for strength (shown in FIG. 11D), but many fastener R may be any kind of fastener that will secure tab cutout 118 reliably. Therefore, fastener R may be a rivet, screw, bolt-and-nut, adhesive, or any other suitable fastener.

Each bulkhead rib 112 and 114 respectively, also has a number of outer tabs 124 (See FIG. 11B). A base 126 (See FIG. 11C) is provided with a number of openings 128 for receiving outer tabs 124 of bulkhead ribs 112 and 114. While openings 128 are in the form of slits, openings 128 may be moved to the edge of base 126 such that the openings 128 are in the form of notches. Base 126 may be made from rubber or from metal. After base 126 is attached to bulkhead ribs 112 and 114, a spacer 129 is attached to the bottom of base 126, resulting in the assembled configuration shown in FIG. 11D as a section view. It should be noted that if base 126 is rubber, that base 126 and spacer 129 may be made as a single piece. If base 126 is made of metal, it is preferred that spacer 129 be made of a foam, rubber, or other pliable material.

An alternate bulkhead assembly construction for bulkhead assemblies 180, 182, 184, 186, and 188 is shown in FIGS. 12A and 12B. As in FIG. 11B, bulkhead rib 112 has tab cutout 118 extending from the upper portion of bulkhead rib 112. In this alternate embodiment, bulkhead rib 114 has opposite tab cutout 119 which extends from the bottom portion, rather than the upper portion. Therefore, tab cutouts 118 and 119 form a rectangular box. Spacers 125 are then applied for contact with reflective film 104. Spacers 125 may be of foam, rubber, or other soft material. Alternatively, in lieu of spacers 125, a single spacer 127 may be placed to cover the edges of bulkhead ribs 112 and 114.

Referring now to FIG. 13A, a further alternate bulkhead rib construction is shown. Bulkhead rib 112 in FIG. 13A is bent at the dotted lines to form a three-sided rib (FIG. 13C). Base 126 is then fixed to bulkhead rib 112, and then a spacer 129 is then applied. It should be noted that any spacers, 125, 127, or 129 are suitable. In addition, as mentioned above, openings 128 on base 126 may be in the form of notches formed on the outer edge of base 126. This variation is shown in FIG. 13C, where tabs 124 are placed within openings 128 which are in the form of a series of notches. Because of this, tabs 124 may be bent towards the center of base 126 to assist in retaining tabs 124 within the notch openings 128.

Referring now to FIGS. 14A, 14B, and 14C, end bulkhead 180 is provided with additional width at the base 200. This additional width allows double spring 202A, 202B, which is fixed in the center by bolt 204A and nut 204B, to apply tension or exert a pulling force on reflective film 104 (which is wrapped around core 84 which is disposed in clamp 80) via clamp 80. As best seen in FIG. 14C, the end of first spring section 202A extends through slot 108, while the other end (second spring section 202B) extends through slot 110. Because reflective film 104 will lengthen from applied tension and higher temperatures, and will shorten from lower temperature, slots 108 and 110 are given adequate length to allow the end of each spring section 202A, 202B to move as reflective film 104 becomes longer and shorter while applying a consistent tension to reflective film 104. It should be noted that there are a number of ways, as seen earlier with respect to FIGS. 7A, 7B, and 7C to secure the end of reflective film 104 prior to connection with spring section 202A and 202B.

Also seen in FIG. 14B is a strap 216. The function of strap 216 is provided in greater detail in the description and drawings associated with FIGS. 15A and 15B.

Referring now to FIGS. 15A and 15B, an adjustable clamp 210 is connected at one end of middle bulkhead 182. The other end is connected to strap 216. An identical structure may be disposed on the other end of middle bulkhead 182 such that the strap 216 traverses substantially the entire length of the outside convex contour of middle bulkhead 182. However, it is preferred that at the other end of middle bulkhead 182, strap 216 be placed in direct contact with the end of middle bulkhead 182. Specifically, because strap 216 is preferably made from a relatively thick metal, one end of strap 216 may be formed into a hook-like shape for contact with the other end of middle bulkhead 182. Therefore, only one side of strap 216 need be provided with an adjustable clamp 210. On the reflective side, reflective film 104 is in contact with the convex outer contour of middle bulkhead 182. On the non-reflective side, reflective film 104 is in contact with strap 216. In other words, reflected film 104, which is in tension by the application of oppositely pulling forces applied at end bulkheads 180 and 188, is disposed between strap 216 and the convex outer contour of middle bulkhead 182. Strap 216 resists any increase in convexity of middle bulkhead 182. Strap 216 also prevents any tendency of lateral movement of reflective film 104 away from any middle bulkhead in the presence of strong wind forces. It should be noted that while clamp 210 is adjustable, via bolt-and-nut assembly 214, an alternate embodiment allows clamp 210 to be fixed, with the length adjustment being made by strap 216 through the use of a buckles (not shown).

In the preferred embodiment, the use of strap 216 in combination with middle bulkhead 182 is repeated for each of the other interior bulkheads, namely, center bulkhead 184 and middle bulkhead 186. As seen in FIG. 14B earlier, strap 216 may also be used at the end bulkheads, 180, 188. Therefore, in the present invention, there could be a strap 216 utilized for each bulkhead 180, 182, 186, 188, although it is also understood that any particular strap or set of straps could also be omitted.

As seen in both FIG. 10 and FIG. 15A, bulkhead 182 is pivotally attached at pin 220 to fixed point 224. Similarly, as seen in FIG. 10, bulkhead 184 is pivotally attached at pin 222 to fixed point 226.

Referring now to FIGS. 16A, 16B, and 16C, three separate support rod patterns are shown. These support rod patterns are preferably applied in the embodiment shown in FIG. 10, but were been omitted from FIG. 10 for clarity. These three support rod patterns are shown here separately in FIGS. 16A, 16B, and 16C in greater detail.

It is emphasized that the term “support rod” as used with respect to FIGS. 16A, 16B, and 16C is intended to include within its meaning a cable, or braided cable, as in FIGS. 2A and 2C. Thus, in the original language of the parent patent application, the term “bracing wires” was used. Since the filing of the parent patent application, it has now been determined that alternate structures may be the best way to carry out the invention, even though the original cable or braided cable will work. Thus, the term “support rod” as used with respect to FIGS. 16A, 16B, and 16C should be understood to refer to along object consisting of a solid cylindrical material such as metal, or consisting of a hollow cylindrical material such as metal, or consisting of a thick wire, or consisting of a braided wire, with the preferred approach being that the “support rod” be made from a solid cylindrical material such as metal.

The first support rod pattern is a vertical, cross-post arrangement, and is shown in FIG. 16A. Specifically, at end post 138, support rod 230 is connected at an upper location and traverses diagonally downward to connect at a lower location to middle post 136. Support rod 232 is connected to end post 138 at a lower location and traverses diagonally upward to connect at a higher location to middle post 136.

At middle post 136, support rod 234 is connected at an upper location and traverses diagonally downward to connect at a lower location to connect to center post 134. At middle post 136, support rod 236 is connected at a lower location and traverses diagonally upward to connect at a higher location to center post 134.

At center post 134, support rod 238 is connected at an upper location and traverses diagonally downward to connect at a lower location to connect to middle post 132. At center post 134, support rod 240 is connected at a lower location and traverses diagonally upward to connect at a higher location to middle post 132.

At middle post 132, support rod 242 is connected at an upper location and traverses diagonally downward to connect at a lower location to connect to end post 130. At middle post 132, support rod 244 is connected at a lower location and traverses diagonally upward to connect at a higher location to end post 130.

This first support rod pattern places all support rods 230-244, respectively in tension, forming opposite diagonals, that are substantially planar, between pairs of support rods 230-232, 234-236, 238-240, respectively. The purpose of the first pattern of support rods is to maintain the posts, 132-138 in parallel, and to prevent any one post from becoming skew with respect to any adjacent post.

In FIG. 16B, the second support rod pattern is shown as a substantially planar pattern. Specifically, in the second support rod pattern, support rod 250 connects end post 138 to one end of middle bulkhead 186, while support rod 252 connects end post 138 to the other end of middle bulkhead 186. Support rod 254 connects middle bulkhead 186, at the same end as support rod 250, to center post 134. Support rod 256 connects middle bulkhead 186, at the same end as support rod 252, to center post 134. Support rods 250, 252, 254 and 256 are preferably substantially planar. Support rod 258 connects center post 134 to one end of middle bulkhead 182. Support rod 260 connects center post 134 to the other end of middle bulkhead 182. Support rod 262 connects middle bulkhead 182, at the same end as support rod 258, to end post 130. Support rod 262 connects middle bulkhead 182, at the same end as support rod 260, to end post 130. Support rods 258, 260, 262 and 264 are preferably substantially planer, and preferably substantially planar with the group of support rods 250, 252, 254, and 256. The purpose of the second pattern of support rods is to maintain the bulkheads, 180-186, in parallel and to prevent any one bulkhead from becoming skew with respect to any adjacent bulkhead.

The third pattern of support rods is shown in FIG. 16C. In this third pattern, support rod 270 connects one end of end bulkhead 188 to an upper location on middle post 136. Support rod 272 connects the other end of end bulkhead 188 to an upper location on middle post 136. It is preferred that the upper location on middle post 136 in this third pattern of support rods be above the upper connection location on middle post 136 for the support rods in the first pattern of support rods. Support rod 274 connects an upper location on middle post 136 to an end of center bulkhead 184. Support rod 276 connects an upper location on middle post 136 to the other end of center bulkhead 184. The upper connection location for support rods 274, 276, is preferably at the same height as the connection height for support rods 270, 272.

Still referring to the third pattern of support rods in FIG. 16C, support rod 278 connects one end of center bulkhead 184 to an upper location on middle post 132. Support rod 280 connects the other end of center bulkhead 184 to an upper location on middle post 132. It is preferred that the upper location on middle post 132 in this third pattern of support rods be above the upper connection location on middle post 132 for the support rods in the first pattern of support rods. Support rod 282 connects an upper location on middle post 132 to an end of end bulkhead 180. Support rod 274 connects an upper location on middle post 132 to the other end of end bulkhead 180. The upper connection location for support rods 278, 280, is preferably at the same height as the connection height for support rods 282, 284.

The third pattern of support rods serves to prevent torsion of the various bulkheads.

It should be appreciated that the combination of the straps 216 on the reverse side of the middle bulkheads in combination with the second and third pattern of support rods (FIGS. 16B and 16C) help distribute external wind forces and therefore prevent any flexing of the entire col lector 100. Because the entire col lector 100 is prevented from flexing in any direction, the reflective surface 104 maintains its concave shape and therefore is able to consistently reflect light from the sun to the focus F.

In FIG. 17A and FIG. 17B, there is shown aright plan view of the solar collector 100. In particular, FIG. 17B illustrates the right plan view of solar collector 100 in a fully deployed position—which position is the one also shown in FIG. 10. As best seen in FIGS. 17A and 17B, support rod 152 is comprised of a first rod section 152A and a second rod section 152B. Similarly, support rod 154 is comprised of a first rod section 154A and a second rod section 152B. End bulkhead 180 is comprised of a first end bulkhead section 180A and a second end bulkhead section 180B. These separate sections were not shown in FIG. 10 for clarity. However, as seen in FIG. 17A, the separate sections pivot to lock into a deployed position, but can be unlocked to pivot into a stored position which takes up less space. In the stored position, it is preferred that reflective film 104, straps 216, and the support rod patterns in FIGS. 16A, 16B, and 16C be removed.

While FIG. 17A shows solar collector 100 collapsing shape along one plane, FIG. 18A shows that solar collector collapses shape along another plane. FIG. 18A is a front plan view showing that the upper rod (106) section 190 and the longitudinal spine (108) section 192 comprise first upper rod section 190A, second upper rod section 190B, first longitudinal spine section 192A, and second longitudinal spine section 192B. These individual sections were omitted from FIG. 10 for clarity. FIG. 18B shows solar collector 100 in a fully deployed position, which is the same position shown in FIG. 10.

FIG. 18A shows that the first upper rod section 190A and second upper rod section 190B may unlock and pivot with respect to each other and with respect to connected posts 134 and 132, respectively. Similarly, first longitudinal spine section 192A and second longitudinal spine section 192B may unlock and pivot with respect to each other and with respect to connected posts 134 and 132 respectively. In this way, after collapsing along the plane shown in FIG. 17A, solar collector 100 may be collapsed further along the remaining plane as shown in FIG. 18A. This allows for a more compact shape. The benefits of such a compact shape are that it allows a significant amount of assembly to take place at a location remote from the deployed location; it permits a lesser amount of assembly (and thus fewer on-site hours and fewer on-site workers) to take place at the deployed location; it permits an easier shipping profile; and it permits the opportunity to “shut down” the solar collector from operation in anticipation of a significant weather event, and then re-deploy—without a significant investment in man hours or heavy equipment.

In another aspect of the invention, there are provided various ways to enhance the stability of reflective film 104 in FIGS. 19A, 19B, 190, 19D, and 19E. For example, it is preferred that an expanding, hardening foam 290 be applied to the non-reflective, convex side of reflective film 104. As shown in FIG. 19A, the foam 290 may be applied after solar collector 100 has been fully deployed. Specifically, foam 290 may be applied in an “X” pattern. It is further preferred that the foam 290 be applied to provide an arch cross section as shown in FIG. 19B. In order to shape such a cross section, the inventor has conceived of a foam shaping tool 292. Such foam shaping tool 292 attaches at one end 294 to a nozzle 296 of a can 298 of expanding, hardening foam 290. The other end 300 of foam shaping tool 292 provides an arch shape such that foam exiting the end 300 assumes the arch shape shown in FIG. 19B. When dried, the foam 290 provides structural stiffness to the convex side of reflective film 104. The additional stiffness inhibits reflective film 104 from flapping or rippling in the wind.

With respect to FIGS. 19D and 19E, which also show the non-reflective, convex side of reflective film 104, an additional or alternate approach to inhibit reflective film 104 from flapping or rippling in the wind is to apply a rigid flange 302 to the non-end bulkhead 180, 188 ends of reflective film 104. As seen in FIG. 19E which is a section view taken from section line 19E in FIG. 19D, an elastic spacer 304 is placed between reflective film 104 and flange 302. Elastic spacer 304 is preferably a double-adhesive foam strip, or other elastic material. The elasticity of elastic spacer 304 allows it to expand or contract with any expansion or contraction of reflective film 104, while maintaining contact with flange 302 which has a much lower coefficient of expansion (and/or lower coefficient of contraction). This buffering provided by elastic spacer 304 prevents reflective film 104 from the greater potential of tearing or ripping that would be present in the case of the direct application of flange 302 to reflective film 104.

With foam 290, straps 216, flange 302, tension producing end bulkhead clamps 203, and the convex outer contour of bulkhead assemblies 110, the reflective film 104 is maintained in position with minimal movement or flapping. With the support rod structures, bulkhead assemblies 110, and the straps 216, the structural components of solar collector 100 are maintained geometrically consistent.

Accordingly, the present invention provides an improved way of collecting and concentrating sunlight, and further provides easier deployment and takedown.

As various modifications could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. For example, reflective film 104 may be replaced by a solar-energy absorbing member 104A, such as a solar cell or a thin-film solar cell. In other words, rather than reflecting concentrated light from the sun via reflective film 104, sunlight is absorbed directly by solar-energy absorbing member 104A. In such a case, the contour of bulkhead ribs 180, 182, 184, 186 and 188 would be modified to a shallower trough shape, or even to a planar shape. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. 

1. A solar collector, comprising: a reflective member having a reflective surface for reflecting light, and an opposite surface; a longitudinally-extending spine; first and second end bulkheads connected to said spine, each bulkhead having an outer contour supporting said reflective surface of said reflective member; a middle bulkhead connected to said spine, between said first and second end bulkhead, having an outer contour supporting said reflective surface of said reflective member, and a first and a second end; and a first strap disposed along said opposite surface of said reflective member, with each end of said strap being connected to one of said first end and said second end of said middle bulkhead.
 2. The solar collector according to claim 1, further comprising: a first post connected to said longitudinally-extending spine and connected to said first end bulkhead, said first post extending in a normal direction from said longitudinally-extending spine away from the reflective surface of said reflective member; a second post connected to said longitudinally-extending spine and connected to said middle bulkhead, said second post extending in a normal direction from said longitudinally-extending spine away from the reflective of said reflective member; and a third post connected to said longitudinally-extending spine and connect to said second end bulkhead, said third post extending in a normal direction from said longitudinally-extending spine away from the reflective surface of said reflective member.
 3. The solar collector according to claim 2, further comprising: a first set of support rods comprising first and second support rods attached diagonally between said first post and said second post; a second set of support rods comprising third, fourth, fifth, and sixth support rods, said third support rod being attached between said first post and one end of said middle bulkhead, said fourth support rod being attached between said second post and the other end of said middle bulkhead, said fifth support rod being attached between said second post and one end of said middle bulkhead, said sixth support rod being attached between said second post and the other end of said middle bulkhead, wherein said second set of support rods are substantially in the same plane; and a third set of support rods comprising seventh, eighth, ninth, and tenth support rods traversing substantially above the plane of said second set of support rods, said seventh support rod being attached between said second post and one end of said first end bulkhead, said eighth support rod being attached between said second post and the other end of said first end bulkhead, said ninth support rod being attached between said second post and one end of said second end bulkhead, said tenth support rod being attached between said second post and the other end of said second end bulkhead.
 4. The solar collector according to claim 1, wherein said outer contour of said first end bulkhead, said outer contour of said second end bulkhead, and said outer contour of said middle bulkhead are trough-shaped.
 5. The solar collector according to claim 1, further comprising: a first clamp having a first end and a second end, and having an adjustable length, said first end of said first clamp being attached to said first end of said middle bulkhead, said second end of said first clamp being attached to an end of said first strap; such that said first strap is indirectly connected to said first end of said middle bulkhead.
 6. The solar collector according to claim 1, wherein said first strap is adjustable in length.
 7. The solar collector according to claim 1, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib, and a plurality of edge tabs along one edge; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib, and a plurality of edge tabs along one edge; and a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 8. The solar collector according to claim 1, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib at an upper location of said first bulkhead rib; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib at a lower location of said second bulkhead rib; wherein said first tab cutout of said first bulkhead rib is fixed to said second bulkhead rib at an upper location of said second bulkhead rib; and wherein said second tab cutout is fixed to said first bulkhead rib at a lower location of said first bulkhead rib.
 9. The solar collector according to claim 1, wherein said end bulkhead further comprises: a first bulkhead rib having a first side with a first plurality of edge tabs, a second side normal to said first side, a third side with a second plurality of edge tabs, said third side being disposed normal to said second side and parallel to said first side; a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said first plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said second plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 10. The solar collector according to claim 1, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; and wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine.
 11. The solar collector according to claim 1, further comprising: said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 12. The solar collector according to claim 1, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine; and said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 13. The solar collector according to claim 1, further comprising: a spring; a clamp attached to said reflective member; and wherein said spring is attached to said clamp and to said first end bulkhead.
 14. The solar collector according to claim 1, further comprising: a hardened foam disposed on said opposite surface of said reflective member.
 15. The solar collector according to claim 1, further comprising: a spacer disposed on said opposite surface of said reflective member; and a flange disposed on said spacer.
 16. A solar collector, comprising: a reflective member having a reflective surface for reflecting light, and an opposite surface; a longitudinally-extending spine; first and second end bulkheads connected to said spine, each bulkhead having an outer contour supporting said reflective surface of said reflective member, and each bulkhead having a first and a second end; and a first strap disposed along the outer surface of said end bulkhead, with each end of said strap being connected to one of said first and said second end of said end bulkhead.
 17. The solar collector according to claim 18, wherein said outer contour of said first end bulkhead, said outer contour of said second end bulkhead, and said outer contour of said middle bulkhead are trough-shaped.
 18. The solar collector according to claim 18, further comprising: a first clamp having a first end and a second end, and having an adjustable length, said first end of said first clamp being attached to said first end of said first end bulkhead, said second end of said first clamp being attached to an end of said first strap; such that said first strap is indirectly connected to said first end of said middle bulkhead.
 19. The solar collector according to claim 18, wherein said first strap is adjustable in length.
 20. The solar collector according to claim 18, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib, and a plurality of edge tabs along one edge; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib, and a plurality of edge tabs along one edge; and a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 21. The solar collector according to claim 18, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib at an upper location of said first bulkhead rib; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib at a lower location of said second bulkhead rib; wherein said first tab cutout of said first bulkhead rib is fixed to said second bulkhead rib at an upper location of said second bulkhead rib; and wherein said second tab cutout is fixed to said first bulkhead rib at a lower location of said first bulkhead rib.
 22. The solar collector according to claim 18, wherein said end bulkhead further comprises: a first bulkhead rib having a first side with a first plurality of edge tabs, a second side normal to said first side, a third side with a second plurality of edge tabs, said third side being disposed normal to said second side and parallel to said first side; a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said first plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said second plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 23. The solar collector according to claim 18, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; and wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine.
 24. The solar collector according to claim 18, further comprising: said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 25. The solar collector according to claim 18, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine; and said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 26. The solar collector according to claim 18, further comprising: a spring; a clamp attached to said reflective member; and wherein said spring is attached to said clamp and to said first end bulkhead.
 27. The solar collector according to claim 18, further comprising: a hardened foam disposed on said opposite surface of said reflective member.
 28. The solar collector according to claim 18, further comprising: a spacer disposed on said opposite surface of said reflective member; and a flange disposed on said spacer.
 29. The solar collector according to claim 18, wherein said first and second end bulkheads further comprise: a convex surface supporting said reflective member.
 30. A solar collector, comprising: a solar-energy absorbing member having an absorbing surface for absorbing sunlight, and an opposite surface; a longitudinally-extending spine; first and second end bulkheads connected to said spine, each bulkhead having an outer contour contacting said absorbing surface of said solar-energy absorbing member; a first strap disposed along the outer surface of said end bulkhead, with each end of said strap being connected to one of said first and said second end of said end bulkhead.
 31. The solar collector according to claim 30, wherein said outer contour of said first end bulkhead, said outer contour of said second end bulkhead, and said outer contour of said middle bulkhead are trough-shaped.
 32. The solar collector according to claim 30, further comprising: a first clamp having a first end and a second end, and having an adjustable length, said first end of said first clamp being attached to said first end of said first end bulkhead, said second end of said first clamp being attached to an end of said first strap; such that said first strap is indirectly connected to said first end of said middle bulkhead.
 33. The solar collector according to claim 30, wherein said first strap is adjustable in length.
 34. The solar collector according to claim 30, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib, and a plurality of edge tabs along one edge; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib, and a plurality of edge tabs along one edge; and a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 35. The solar collector according to claim 30, wherein said end bulkhead further comprises: a first bulkhead rib having a first tab cutout extending away from said first bulkhead rib at an upper location of said first bulkhead rib; a second bulkhead rib having a second tab cutout extending away from said second bulkhead rib at a lower location of said second bulkhead rib; wherein said first tab cutout of said first bulkhead rib is fixed to said second bulkhead rib at an upper location of said second bulkhead rib; and wherein said second tab cutout is fixed to said first bulkhead rib at a lower location of said first bulkhead rib.
 36. The solar collector according to claim 30, wherein said end bulkhead further comprises: a first bulkhead rib having a first side with a first plurality of edge tabs, a second side normal to said first side, a third side with a second plurality of edge tabs, said third side being disposed normal to said second side and parallel to said first side; a base having a first plurality of edge-tab-receiving-openings on one side and a second plurality of edge-receiving-tab-openings on the other side, said first plurality of edge tabs of said first bulkhead rib being extended through said first plurality of edge-receiving-tab-openings of said base, and said second plurality of edge tabs of said second bulkhead rib being extended through said second plurality of edge-tab-receiving-openings of said base.
 37. The solar collector according to claim 30, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; and wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine.
 38. The solar collector according to claim 30, further comprising: said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 39. The solar collector according to claim 30, wherein said first end bulkhead further comprises a first portion and a second portion: wherein said first portion of said first end bulkhead is pivotally attached to said longitudinally-extending spine; wherein said second portion of said first bulkhead is pivotally attached to said longitudinally-extending spine; and said longitudinally-extending spine having a first portion and a second portion pivotally connected together.
 40. The solar collector according to claim 30, further comprising: a spring; a clamp attached to said solar-energy absorbing member; and wherein said spring is attached to said clamp and to said first end bulkhead.
 41. The solar collector according to claim 18, further comprising: a hardened foam disposed on said opposite surface of said solar-energy absorbing member.
 42. The solar collector according to claim 18, further comprising: a spacer disposed on said opposite surface of said solar-energy absorbing member; and a flange disposed on said spacer.
 43. The solar collector according to claim 18, wherein said first and second end bulkheads further comprise: a convex surface supporting said solar-energy absorbing member. 